Memory element and memory device

Abstract

There is disclosed an information storage element including a first layer including a ferromagnetic layer with a magnetization direction perpendicular to a film face; an insulation layer coupled to the first layer; and a second layer coupled to the insulation layer opposite the first layer, the second layer including a fixed magnetization so as to be capable of serving as a reference of the first layer. The first layer is capable of storing information according to a magnetization state of a magnetic material, and the magnetization state is configured to be changed by a spin injection. A magnitude of an effective diamagnetic field which the first layer receives is smaller than a saturated magnetization amount of the first layer.

The application is claimed as follows: 
     
       1. A storage element comprising:
 a first layer having a magnetization state of a first magnetic material; 
 a second layer having a fixed magnetization state of a second magnetic material; 
 an intermediate layer including a nonmagnetic material and being interposed between the first layer and the second layer; 
 wherein the first layer is configured to store information according to the magnetization state of the first magnetic material, 
 wherein a magnitude of an effective diamagnetic field which the first layer receives is smaller than a saturated magnetization amount of the first layer, 
 wherein the first magnetic material includes Co, Fe, and B, where the amount of B ranges from greater than 20 at % to 40 at %, and where the amount of Fe ranges from 36 at % to less than 80 at %, and 
 wherein a ratio of Co and Fe in the first magnetic material which includes the Co, Fe and B is 7 to 3. 
 
     
     
       2. The storage element according to  claim 1 , wherein the first magnetic material includes a ferromagnetic material. 
     
     
       3. The storage element according to  claim 1 , wherein the magnetization state of the first magnetic material is configured to be changed by a current. 
     
     
       4. The storage element according to  claim 1 , wherein the second magnetic material includes Co, Fe, and B. 
     
     
       5. The storage element according to  claim 1 , wherein the intermediate layer includes at least one of magnesium oxide, aluminum oxide, aluminum nitride, SiO 2 , Bi 2 O 3 , MgF 2 , CaF, SrTiO 2 , AlLaO 3 , and AlNO. 
     
     
       6. The storage element according to  claim 1 , further comprising a cap layer. 
     
     
       7. The storage element according to  claim 6 , wherein the cap layer includes Ru or Ta. 
     
     
       8. The storage element according to  claim 7 , wherein the cap layer includes a laminated film including a first Ta film, a second Ta film, and a Ru film formed between the first and second Ta films. 
     
     
       9. The storage element according to  claim 1 , further comprising an underlying layer. 
     
     
       10. The storage element according to  claim 9 , wherein the underlying layer includes Ru or Ta. 
     
     
       11. The storage device according to  claim 10 , wherein the underlying layer includes a laminated film of a Ta film and a Ru film. 
     
     
       12. The storage device according to  claim 1 , wherein a film thickness of the second layer is greater than a film thickness of the first layer. 
     
     
       13. The storage device according to  claim 1 , wherein a damping constant of the second layer is greater than a damping constant of the first layer. 
     
     
       14. The storage device according to  claim 1 , wherein the second layer has a laminated ferri-pin structure including two ferromagnetic layers and a non-magnetic layer. 
     
     
       15. The storage device according to  claim 14 , further comprising an anti-ferromagnetic layer applied to the laminated ferri-pin structure. 
     
     
       16. The storage device according to  claim 1 , wherein a magnetization direction of the first magnetic material is perpendicular to a substrate of the storage device. 
     
     
       17. A memory device, comprising:
 an storage element that retains information through a magnetization state of a magnetic material; and 
 two kinds of interconnects that intersect each other, 
 wherein the storage element includes 
 a first layer having a magnetization state of a first magnetic material; 
 a second layer having a fixed magnetization state of a second magnetic material; 
 an intermediate layer including a nonmagnetic material and being interposed between the first layer and the second layer; 
 wherein the first layer is configured to store information according to the magnetization state of the first magnetic material, 
 wherein a magnitude of an effective diamagnetic field which the first layer receives is smaller than a saturated magnetization amount of the first layer, 
 wherein the first magnetic material includes Co, Fe, and B, where the amount of B ranges from greater than 20 at % to 40 at %, and where the amount of Fe ranges from 36 at % to less than 80 at %, and 
 wherein a ratio of Co and Fe in the first magnetic material which includes the Co, Fe and B is 7 to 3. 
 
     
     
       18. The storage device according to  claim 1 , wherein the amount of B ranges from greater than 30 at % to 40 at %. 
     
     
       19. The memory device according to  claim 17 , wherein the amount of B ranges from greater than 30 at % to 40 at %.